Facilities for the reprocessing of irradiated nuclear fuel materials are equipped with so-called hot cells for holding the components needed for conducting the industrial processes associated therewith. In these radiation-shielded cells, the process components are arranged in scaffold-like structures or racks as they are sometimes referred to.
The maintenance work within the hot cell affected by radioactive radiation should be conducted preferably without the necessity of operating personnel entering the hot cell. Solutions have been therefore sought to conduct the maintenance work by means of remotely-controlled equipment which can be movable within the hot cell. For this purpose, it is desirable that the racks holding the components used in the industrial processes be arranged in mutually adjacent rows longitudinally along the walls of the hot cell. In this way, a center passageway is formed along which the remotely-controlled equipment for the maintenance work can be moved and for exchanging the individual process components or exchanging fully-loaded racks.
For the maintenance work and the exchange of individual process components or of entire racks, a combination of remotely-controlled machines for performing manual-like operations are utilized. The overhead bridge crane passes over both rows of racks and the center passageway. After all connections and conduits are disconnected, the racks or heavy individual components are lifted from their anchor locations with the aid of the overhead bridge crane. The bridge crane then moves the racks or individual components horizontally into the transport passageway. The control room for the remotely-controlled bridge crane is located outside of the hot cell.
In addition to the overhead bridge crane, a manipulator carrier apparatus is provided which can act in the horizontal direction from the central transport passageway to engage the process components and to position operating devices, maintenance device and tools. This manipulator carrier apparatus opens up the possibility for utilizing electrical servo and power manipulators as well as providing the capability for the future use of robots and programmed apparatus. Manual-like operations are performed on small components with the available manipulators and lifting devices in dependence upon the configuration of the carrier apparatus.
The manipulator carrier apparatus includes a vertical guide column arranged on a second overhead bridge crane movable below the first overhead bridge crane in the direction of the longitudinal axis of the hot cell; or, if desired, the column can be mounted on a half bridge movable below the overhead bridge crane. The rotatable guide column includes an extendable arm mounted on a support which can be moved vertically up and down. The extendable arm is adapted to receive the tools or equipment for performing manual-like operations. A division of work is achieved with the arrangement of the first overhead bridge crane and the manipulator carrier apparatus. The remotely-controlled first overhead bridge crane is used primarily for holding and transporting pipe connections, components and individual racks. If necessary, the first overhead bridge crane can take over the lowering and holding of tools as well as separating and welding equipment. The manipulator carrier apparatus which is movable along the central passageway serves to guide and hold impact wrenches or other special tools which are needed to effect disassembly work. Further, the manipulator carrier apparatus and second overhead bridge crane can be adapted for accommodating video equipment or other helpful ancilliary devices.